On Tue, Nov 18, 2025 at 9:45 PM ToddAndMargo via perl6-users <perl6-
[email protected] <mailto:[email protected]>> wrote:
Hi All,
I am a bit confused as to what colon pairs are actually doing:
[0] > my $y=:abc;
abc => True
Why is this True and not Nil?
[1] > my $y=:abc(123);
abc => 123
This I get.
[2] > my $y=:abc();
abc => ()
Why is this () and not Nil?
[3] > my $y=:abc(Nil);
abc => Nil
This I get
Yours in Confusion,
-T
On 11/18/25 11:29 PM, Sean McAfee wrote:
It's all spelled out here: https://docs.raku.org/language/
glossary#Adverbial_pair <https://docs.raku.org/language/
glossary#Adverbial_pair>
Notice in particular that :foo means :foo(True) and :!foo
means :foo(False). Also see that
[...] other circumfix operators with their usual semantics can be used
for stating the value, e.g. |:foo[…]| for an array and |:foo{…}| for a
hash or even a |Block|.
Therefore :foo() means a Pair whose key is the string "foo" and whose
value is the empty list. Compare with :foo(1, 2, 3) which is the same
as foo => (1, 2, 3).
Thank you!
So no Nil. <sniff, sniff> :'(
